Synthesis of One-Handed Helical Block Copoly(substituted acetylene)s Consisting of Dynamic cis-transoidal and Static cis-cisoidal Block: Chiral Teleinduction in Helix-Sense-Selective Polymerization Using a Chiral Living Polymer as an Initiator.

Abstract

By using a living one-handed helical cis-transoidal poly(chiral substituted phenylacetylene) as a polymer initiator (poly(1n)), helix-sense-selective polymerization (HSSP) of an achiral phenylacetylene 2 having two hydroxy groups successfully afforded a diblock copoly(phenylacetylene) (copoly(1n/2m)) consisting of a dynamic one-handed helical cis-transoidal block and a static one-handed helical cis-cisoidal block. The formation of the diblock structure was confirmed by consumption of the chiral initiator, appearance of characteristic CD indicating the one-handed helical cis-cisoidal block, and occurrence of the selective photocylic aromatization reaction in the cis-cisoidal block. Therefore, HSSP has been achieved by using the chiral alkenyl groups in the initiator as a chiral source for the first time. In addition, since the HSSP was achieved in spite of the long distance between the chiral initiation site and the propagating site, chiral teleinduction through the rigid and static one-handed helical cis-cisoidal block based on domino effects was confirmed.